Although I haven't been there for a while, I've driven considerably out of my way to go to La Bodega Mexican Restaurant in Midland.

They have some of the best chiles rellenos I've ever tasted, at least north of the border. They stuff them with picadillo and they're wonderful.

Although as I said, it's been a while since I've been up that way, and if you're interested in going there, it's probably worth a phone call first to see if they're still making that particular type of chiles rellenos.